The concentrations of various total and dissolved metals parameters may be present at varying concentrations in soil, surface water, or groundwater, and often exceed applicable regulatory guideline values. Employing methods to properly characterize potential metal impacts and background conditions excludes naturally elevated inorganic parameters as potential chemicals of concern and eliminates unnecessary investigation, risk assessment, and/or remediation. Elevated metals in background can be the result of weathering, various geological formations and parent material, soil type (i.e., highly mineralized soil [clay]), soil inclusions (i.e., coal), groundwater conditions (i.e., aerobic versus anaerobic environments), and/or naturally occurring geochemistry processes (i.e., dissolution). Many factors affect the solubility of metals in terrestrial and aquatic environments such as pH, redox conditions, and temperature.

The guideline values for total and dissolved metals parameters are often equal to or the same order of magnitude as laboratory detection limits, often resulting in suspect exceedances of applied guidelines since results are within the margin of error of the analytical method used. This is a commonly encountered issue in environmental investigations along with considerable variability in metals datasets.

Chemistry Matters Inc. (CMI) has extensive experience characterizing various anthropogenic and naturally occurring sources in soil or water using total and dissolved metals data, isotope analyses, association analyses, and/or statistical approaches. In addition, CMI specializes in oil and water fingerprinting using isotopes and total and dissolved metals data. Fingerprinting techniques are valuable in source determination and characterization and have been applied by CMI in various litigation projects and liability evaluations. For example, metals fingerprinting can be used to ascertain which geologic formation in an oil and gas field is the source of a fluid release (i.e., produced water). With the overwhelming number of potential unique markers present in oil and refined products, in depth knowledge of these components allows the trained environmental forensics expert to distinguish between even very similar sources.

Figure 1. Extended Metals Analysis used to Distinguish Oil Sources

In addition to fingerprinting and characterization utilizing metals data, CMI can assist with risk evaluations and evaluate mobility and fate and transport of metals impacts in soil or water at a variety of sites in various jurisdictions. Furthermore, CMI has experience performing statistical analyses on a variety of metals parameters and calculating site-specific guidelines based on background samples from the site or the area.